Film treating apparatus and method



. 16, 1932. c. R. HUNTER ET AL 1,845,416

FILM TREATING APPARATUS AND METHOD Filed Jan. 27, 19:50 4 Sheets-Sheet 1 z 1 g 7 2 & I t 1 I Qg Q i F Q W I M x M l Feb. 16, 1932. c. R. HUNTER ET AL FILM TREATING APPARATUS AND METHOD Filed Jan. 27, 1930 4 Sheets-Sheet 2 I Feb. 16, 1932. c, R, HUNTER ET AL 1,845,416

FILM TREATING APPARATUS AND METHOD Filed Jan. 27, 1930 4 Sheets-Sheet 5 Feb. 16, 1932. c, R HUNTER ET AL 1,845,416

FILM TREATING APPARATUS AND METHOD Filed Jan. 27. 1950 4 Sheets-Sheet 4 Patented Feb. 16, 1932 UNITED STATES PATENT, OFFICE CHARLES R. HUNTER AND ROBERT M. ASSIGNORS TO UNIVERSAL PICTURES FORNIA, A CORPORATION NEW YORK FILM TREATING APPARATUS AND METHOD Application filed January 27, 1930. Serial No. 423,729.

This invention relates to film treating apparatus, and more particularly to a method of and means for developing, fixing or otherwise treati'ng, strips of photographic film,

negatives or positives, as the same are produced for projecting motion pictures, or for the printing of other films for the projection of motion pictures.

In the treating or developing of motion picture films, it has heretofore been the practice to develop or treat the said films, either when employin the agent, tank and rack system or metho the drum system and method, or

when employing developing machines of a type wherein a plurality of alternately driven and idler members were employed to cause the film tape to be moved through the successive developing, fixing, washing and drying steps of the process.

When usin the type of developing machine which inclu es the alternately driven and idler members for causing the film tapes to progress through the various stages of the developing or treating process, it is necessary to decrease the concentration of the developing solutions employed to such an extent that the crystals formed on the film during the developin are of increased size, therebydecreasing the quality of the prints or negatives formed in these machines. In these machines the film is caused to traverse through the machines at the rate of several thousand feet per hour. When employing the alternately driven and idler member type developing machine, the film is contacted throughout the machine on rollers at several hundred points throughout the path traversed by the film in passing through the machine. and each of these points of contact forms a point where the film is liable to be scratched or marred.

The moving of films at high speed through developing solutions of relatively low concentration' produces increased grain on the film surface. The crystals formed are larger and the grain effect is multiplied. In accordance with the method and using the apparatus embodying our invention, full concentration solutions may be employed and the film is caused to travel more slowly with the result that the film, when developed, has a much less grain effect.

It has heretofore been found impossible to cause a long tape of film of approximately 1,000 feet in length to be moved through the respective stages of developing, rinsing, fixing, washing and drying without driving the film at a plurality of points through this path because of the alternate elongation and contraction caused in the film due to the first moistening and then drying of the film, and due to the supposed liability of the film tape to break unless properly driven from a plurality of points in such a course of travel.

We have found that a photographic film tape may be conveyed through the respective steps 0 developing, rinsing, fixing, washing and drying in a substantially horizontal position without driving the film tape from a plurality of spaced points through its path, but by merely drawing the film tape through the respective stages of its process in a substantially horizontal position through the developing, fixing, rinsing and washing solutions, and that when so drawn from the exit end of a machine or process, that the film is not subjected to greater liability of breakage or of distortion or even as great a liability to breaking and distortion as when it is caused to pass through a helical path over alternate driven and idler members. We have discovered that the photographic film tapes may be substantially floated in a horizontal position through the required solutions by drawing the film tape from the exit end of the process and without driving the film at any intermediate points.

We have found that when causing the film tape to float through the required solutions for developing or treating, that the concen tration of said solutions may be increased to that required for the production of the most effective or efiicient results, and that the increased concentration of the solutions used over that employable in the types of developing machines heretofore commonly used aids in the floating of the films through the said solutions and gives usa better development of prints or negative films, allowing us to move the films more slowly through the solution to produce a finer crystallization upon the films with a great reduction' of the grain effect.

It is therefore an object of this invention to provide a method of treating and developing photographic film in which the photograp ic films are floated through the solutions in substantially horizontal position and are conveyed through the respective steps of the developing or treating process by being drawn solely from the exit end of the apparatus employed in carrying out theprocess.

Other objects and advantages of this invention it is believed will be apparent from the following detailed description of the preferred embodiment of our invention, a preferred embodiment of which is illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a top plan view of a battery of developing machines embodying our invention.

Figure 2 is a side elevation thereof.

Figure 3 is a detached diagrammatic view illustrating the course of travel taken by the film tape in passing through the machine and when following the method embodying our invention.

Figure 4 is an enlarged fragniental sectional view of thefilm developing apparatus embodying our invention.

Figure 5 is a like fragmental sectional elevation of the opposite end of the film developing machine embodying our invention.

Figure 6 is an end elevation of the film developing machine embodying our invention looking from right to left in Figure 5.

Figure 7 is a sectional edge elevation taken substantially on the line 77 of Figure 4.

Figure 8 is a fragmental sectional plan view of one of the film troughs of our invention.

Figure 9 is an end elevation of the structure illustrated in Figure 8.

Figure 10 is a sectional end view of one of the solution troughs embodied in our invention.

In accordance with the process or method of treating or developing photographic film tapes embodying our invention, the film tape F is unwound from the reel 1, caused to pass through a plurality of troughs 2, 3 and 4 in substantially horizontal position, and through a drier 5, likewise substantially in horizontal position, by the drawing of said film through the said apparatus from the exit end of the said apparatus by causing the film to pass over and be drawn by a driven sprocket 6. The troughs 2, 3 and 4 are filled with treating solutions in which the film is treated or developed to carry out the respective steps of the treating process.

In developing, the trough 2 contains the developing solution, the trough 3 the fixing solution, and the trough 4 a washing solution from the film tape F.

The troughs 2, 3 and 4, and the drier 5,

are superimposed one above the other solely for the purpose of conserving space, and may, if desired, be arranged end to end, or 1n other positions.

Each of the troughs 2, 3 and 4 is preferably formed of wood with a pair of sides 12, a bottom 13, and ends 14. Wood is em ployed, and preferably soft wood, for the reason that the chemicals employed in carrying out the treating or developing process are least affected by wooden troughs, although the troughs may be formed of any other desired substance. The trough 2 is of suflicient length so that the film tape F, when passing through the trough, will be completely developed by the developing solution contained therein. The trough 3 is of suflicient length so that the developed film will be completely fixed when passing through the trough 3. The trough 4 is of suflicient length so that the film will be completely washed when passing through it.

WVe have found that films are best developed When carrying out our process when they are caused to pass through the apparatus at the rate of approximately 600 feet per hour, although the rate of travel may be varied through wide limits. The developing solution is circulated through the trough 2 from the tank 15 through a pipe 1? connecting the pump 16 with one end ofthe trough 2, and the developing solution is returned to the tank 15 through a pipe 18 from the op-.

posite end of the trough 2, the flow of the developing solution being preferably in a direction reverse to the direction of travel of the film F through the trough 2.

Ina like manner, the fixing solution is provided from a tank 19 through a pump 20 and.

pipe 21 to the trough 3, being recirculated to the tank 19 through the pipe 22. The wash water is also circulated through the trough 4 byconnecting the trough 4 by means of a pipe 24 with a source of water under pressure, and draining the opposed end in any suitable or desirable manner to the sewer or other point of disposal of the wash water.

The drier is enclosed in any suitable or desirable manner, and is preferably'formed as a cabinet having glass or transparent sides with glass doors 25, permitting access to the interior thereof. Air is employed in drying the film and is admitted to the drying chamber through a heating chamber 26, and the filter 27, wherein the air is heated by a heating element 28 and filtered by the filter 27 as it is drawn into the chamber 5. The air is caused to pass through the drying chamber 5 by being drawn out from the chamber 5 by means of a blower or fan 29, the intake side of which fan is connected with the exit end of the drying chamber. The fan 29 is driven by a. motor 30.

The film F, passing through each of the troughs 2, 3 or 4, is floated therethrough due to its buoyancy in the solution or washing water contained therein, and is unsupported throughout its length so that it is not contacted with rollers or other elements which tend to scratch or mar the film. In each trough the film is guided into position by means of an idler roller 31.

The film is guided on leaving each of the troughs 2, 3 and 4 by means of idler rollers 32. Between the idler rollers 21 and 32 the film is unsupported in the troughs.

WVe have found that it is a considerable advantage in the developing of photographic films to twist the film in each of the troughs 2, 3 and 4 so that the film is twisted by the rollers 31 and 32. By twisting the film the film is caused to travel through the solutions at varying angular relations, which aids in the developing, fixing and washing of the film, but more important, prevents the contacting of the film surfaces with the sides or bottom of the trough, but if slack is developed between any particular rollers 31 and 32 for any reason, the film will contact the bottom of the trough on its edge, and not on its surface.

The wiping means illustrated in Figure 4 comprises a pair of substantially circular elements upon which chamois skin or other absorbent material is wrapped, the circular members bein illustrated at 33 and being covered with t e chamois 34. The film tape F is caused to contact the chamois on each of the elements-33, and is thereby freed of excess surface moisture before it passesinto the drying chamber 5.

The film F is guided into the drying chamber 5 over idler rollers 35, 36, 37 and 38, and is caused to travel through the drying chamber 5 in a series of horizontally disposed passes 39, 40 and 41, depending solely upon the time re uired for the film to remain in the drying c amber 5 in order to completely dry the film. In order to cause the film F to pass through the passes 39, 40 and 41, the film is guided over the rollers 42 and 43. Each of the rollers 35, 36, 37, 38, 40 and 42 are idler-rollers and are of anyconvenient or desired size.

The sprocket 6 is driven in any suitable or desirable manner such, for example, as by means of a pulley 42, which is secured to the shaft to which the sprocket 6 is secured. The pulley 42 is driven by a belt 43 through a speed reduction element 44 from an electric motor 45. Idler rollers 46 are provided for the purpose of maintaining the film F on the sprocket 6 in a manner well understood in the art. A wind-up reel 47 is provided upon which the film F is wound after having been developed, fixed, washed and dried. The wind-up reel 47 may be driven by any suitable or desirable means such, for example, as by a belt 48 driven from a pulley mounted upon the shaft with the sprocket 6 and pulley 42. The sprocket 6 is frictionally driven.

A frame work is provided in the form of a plurality of spaced uprights 49, upon which the troughs 2, 3 and 4 and drier 5 are supported.

The film F may be caused to travel through a horizontal trough, like those herein illustrated, in the absence of a solution or liquid in the tanks by the causing of the film to travel through the troughs in horizontal position with the liquid in the troughs which insures that the film will not be marred as it is moved through the troughs because the film will be partially supported by its own buoyancy in the liquid, and the liquid provides a lubricant so that if the film contacts the bottom or sides of the trough it will not be scratched or marred. The twisting of the films between the guidemeans employed for guiding the film from each end of the trough aids in maintaining the film from contact with the sides or bottom of the trough on the plain surface of the film.

The solutions which are employed in the horizontally disposed troughs, whether they be positioned end to end, or one vertically over the other, may also be jetted from the bottom of the troughs upwardly to contact the film to maintain the film spaced from the bottom of the the film from tank.

While we'have herein set forth that the troughs employed in accordance with this invention are open troughs, it will be obvious that to merely cover the troughs will not depart from our invention, the use of open troughs being particularly desirable in order to permit easy and instantaneous access to the films during the developing process, but, in some cases as in color photography and the like it will be desirable to provide the troughs with covers to protect the treating solutions.

troughs, thereby maintaining contacting the bottom of the As illustrated in Figure 1, a plurality of developing machines may be positioned side by side and driven from a single source and connected to a common air delivering means, and also to common developing and fixing solution tanks. films may be developed or treated at a single time. A plurality of separate machines may be employed or, if desired, the troughs 2, 3 and 4 and drier 5, may be increased in width and a plurality of films may be caused to In this manner a plurality of travel side by side through a single apparatus.

Having fully described our invention, it is to be understood that we do not wish to be limited to the details herein set forth, but our invention is of the full scope of the appended claims.

lVe claim l. A method of treating films including the drawing of a continuous tape of said film through a series of treating liquids from the exit end of said treating liquids Without driving said films from intermediate points, the said film floating through said liquids in submerged position substantially out of contact with the containers in which the liquids are held.

2. A method of treating films including the drawing of a continuous tape of said film through a series of treating liquids, from the exit end of said treating liquids, guiding the film from one liquid to another, the said film floating through said liquid substantially out of contact with the containers in which the liquids are held.

3. A method of treating photographic film tape including the drawing of a continuous tape of said film through a first liquid, guiding the same to a second liquid, conducting the same through the second liquid, guiding the same to a third liquid, conducting the same through the third liquid, guiding the film tape to a drying chamber, and causing the said film tape to move through the drying chamber, and liquids by pulling the said film therethrough from the exit end of the drying chamber.

4. A method of treating films including drawing the continuous tape of said films through a series of treating liquids, from the exit end of said treating liquids, the liquids being of sufficient density to cause said film to float through said liquid due to its buoyancy substantially out of contact With the containers in which the liquids are held.

5. In an apparatus of the class described, the combination of a series of substantially open troughs, one of said troughs providing a container for a first liquid, the second of said troughs providing a container for a second liquid, and one of said troughs providing a container for a third liquid, means for guiding the film at each end of said troughs, the said films being disposed in said troughs in substantially horizontal position, and being out of contact with guiding means from the entrance to the exit end of each of said troughs, and means for drawing the film continuously through said troughs from the exit end of the latter of said troughs.

6. In an apparatus of the class described, the combination of a series of substantially open troughs, one of said troughs providing a container for a first liquid, the second of said troughs providing a container for a second liquid, and one of said troughs providing a container for a third liquid, means for guiding the film near each end of said trough, the said films being disposed in said troughs in substantially horizontal position, and being out of contact with guiding means substantially throughout the length of each of said troughs, means for drawing the film continuously through said troughs from the exit, end of the latter of said troughs, andimeans for continuously supplying one of said liquids to one of said troughs.

7. In an apparatus of the class described, the combination of a series of substantially open troughs, one of said troughs providing a container for a first liquid, the second of said troughs providing a container for a second liquid, and one of said troughs providing a container fora third liquid, means for guiding the film at each end of said trough, the said films being disposed in said troughs in substantially horizontal position, and being out of contact with guiding means from the entrance to the exit end of each of said troughs, means for drawing the film continuously through said troughs from the exit end of the latter of said troughs, means for continuously supplying the first liquid to the first liquid trough, and means for continuously supplying a second liquid to the second liquid trough.

8. In an apparatus of the class described, the combination of a series of substantially open troughs, one of said troughs providing a container for a first liquid, the second of said troughs providing a container for a second liquid, and one of said troughs providing a container for a third liquid, means for guiding the film at each end of said trough, the said films being disposed in said troughs in substantially horizontal position, and being out of contact with guiding means from the entrance to the exit end of each of said troughs,-means for drawing the film continuously through said troughs from the exit end of the latter of said troughs, means for continuously supplying the first liquid to the first solution trough, means for continuously supplying a second liquid to the second liquid trough, and means for continuously supplying third liquid to the third trough.

9. In an apparatus of the class described, the combination of a series of substantially open troughs, one of said troughs providing a. container for a first liquid, the secondof said troughs providing a'container for a second liquid, and one of said troughs providing a container for a third liquid, means for guiding the film at each end of said trough, the said films being disposed in said troughs in substantially horizontal position, and being out of contact with guiding means from the entrance to the exit end of each of said troughs, means for drawing the film continuously through said troughs from the exit end of the latter of said troughs, means for continuously supplying first liquid to the first liquid trough, means for continuously supplying a second liquid to the second liquid trough, means for continuously supplying third liquid to the third liquid trough, and the said liquids being caused to fiow through said troughs opposite to the direction of travel of the film tape therein.

10. A method of continuously treating motion picture films including the drawing of a continuous tape of said film through a series of treating liquids, the said film passing through each of said liquids in substantially horizontal position, the said film being drawn through said liquids, from the exit end of the last of said liquids, and the said film being maintained out of contact with the containers go in which said liquids are held solely by the tension applied to said film for drawing said film through said solutions and the buoyancy of the film in said liquids as it is moved therethrough. g5 11. In a motion picture film developing apparatus, the combination of a series of solution troughs for containing developing, fixing and rinsing solutions respectively, means at each end of said troughs for guid- 80 ing the film, a drying chamber in the series at the end of the last said trough, means interposed between the last said trough and the drying chamber for removing excess moisture from the film, means for guiding the film in the drying chamber, and means at the exit end of the drying chamber for pulling the film continuously through said troughs and through said drying chamber from the exit end of said drying chamber. Signed at Los Angeles, Calif., this 20th day of January, 1930.

CHARLES R. HUNTER. ROBERT M. PIERCE. 

